Improvement in steam-gauge cocks



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'llIOlV-IASV B. DEXTER, 'O F LYNN, MASSACHUSETTS... Letter@ Patent No.sense, 'emozionata 15, 1867.

'IMPROVEMENT IN STEAM-GAUGE GOGKS.

To ALL WI-IOM IT MAY coNoERN;

Be it known that I, THOMAS B. DEXTER, of Lynn, in the county of Essex,and State ef Massachusetts, have invented. certain new and Ausefulimprovements in`Gauge-Coc`ks for Steam-Boilers; and I do hereby declarethat the following is a full, clear,'and exact description thereof,reference being had to the accompanying drawings, making part of thisspecification` and vto the letters o f reference marked thereon, likeletters indicating like parts wherever they occur- To' enable othersskilled in thelartto construct anduse my invention, I will proceed todescribe it.

My invention consists in a novel construction ofthe shell and valve ofgauge-cocks, by which the valve may be closed by screwing the stem in,and' also by screwing the same outward, so that when one end of thevalve or its seat becomes worn, the other may be used,andthe gauge-cockremain equally efeetivc.

'lhedrawin,r represents a longitudinal seetion,-taken through thecentre.

A represents the shellwhich'1 construct 'of two parts and unite by-ascrew-joint at the centre, the end being provided with'a screw-thread atI in the usual manner for attaching it to the boiler. A hole, (i,extends longitudinally throughA th'e centre from the end to thecentr-:lvchamber B, and is provided with a conical seat, m. at the point where itenters the char'nhr B. t'; theopposite end of said chamber B another andsimilar valve-seat, mis fo-rmerL-from 'whence the passage or openingleads into and connects with another' and smaller chambere, as'shown inthe drawing. Connected with this chamber e is an escape pipe or spout,E, for the escape of the steamer water. From the chamber e the shell isext-ended far enough to atord a bearing for thc valve-stero C,-and'has ascrew-thread, .11., formed on its inner surface corresponding with aAprojecting screwthread cut on the' stem C in the usual manner, theshell terminating with the ordinary cap F, to form a stallingbox aroundthe stem C." The valve-stem C is' reduced in diameter from the pointwhere the thread on it terminutes to the point where the valve e isattached; The valve c consists of a block or plug made conical at eachend, tofit the seats 4m. and n, andsccured firmly to the iriner end ofthe stem C by means of a. pin, o, and also by'being screwed thereon, ifdesired. l l

-With the parts thus constructed and arranged, it will be seen that whenthe valve e is brought back to the 'Seat it the cock isperfectly'closcd, and that when its opposite end is forced forwardagainst't-he seat mit is equally closed; and that, as no steam or watercan escape from pipe E until it enters the second chamber e,

,'the cock can be closed'by eitlxer`a forward or-backn'ard movement ofthe stem C, at pleasure; and hence,

when one end vot' the valve or-its seat becomes worn the other can beused, and the coekthus remain tit for use.

Having thus described my invention, what I claim, is A gauge-'ooohprovided with the doubleheaded valve c, arranged to operate incombination with the valveseats m and n, located at opposite ends of thechamber B, substantially as shown and described.

THOMAS B. DEXTER.

